regexp is not a built in function, the functionality needs to be imported. In the SQLite shell, with a .load /usr/lib/sqlite3/pcre.so directive. create table tq84_regexp (
col text
);
insert into tq84_regexp values ('foo');
insert into tq84_regexp values ('twenty-two: 42');
--
-- pcre.so: needed for regexp--
--
.load /usr/lib/sqlite3/pcre.so
select col from tq84_regexp where col regexp '\d';
--
-- twenty-two: 42
select col from tq84_regexp where col regexp '(.)\1';
--
-- foo
drop table tq84_regexp;
pcro.so might be installed with sudo apt-get install sqlite3-pcre
like_regex, occurrences_regex, position_regex, substring_regex, translate_regex)